1. Field of the Invention
The present invention relates to a pressure regulating device for regulating a pressure applied to an area of a living body to be measured during a measurement of a biological information with the use of an optical biological information measuring apparatus and, more particularly, to the pressure regulating device utilized in the apparatus to ensure a tight contact between the area of the living body and a detecting probe under a predetermined pressure.
2. Description of the Prior Art
An optical biological information measuring apparatus for measuring a biological information (which information is hereinafter referred to as a "biodata") from an area of a living body, for example, from a portion of the palm of a hand of a human being, has been well known in the art and is disclosed in, for example, the Japanese Laid-open Patent Publication No. 6-14906. This optical biodata measuring apparatus comprises a detecting probe for irradiating the area of the living body and also for receiving rays of light transmitted through and/or reflected from the area of the living body, and an optical measuring system for measuring or analyzing spectra of the transmitted and/or reflected light to provide the biodata of interest based on those spectra. The detecting probe generally includes a light emitting element from which the light is irradiated towards the area of the living body and a light receiving element for receiving or detecting the transmitted and/or reflected light and is adapted to contact the area of the living body to be measured during the biodata measurement. When such an optical biodata measuring apparatus is utilized, conditions under which the biodata measurement is carried must be kept constant and, in particular, the pressure applied to and the temperature of the area of the living body must be kept constant throughout the entire cycle of the biodata measurement.
With the optical biodata measuring apparatus of the kind disclosed in the above mentioned publication, the use has been made of a clip or a double-sided adhesive tape to secure the area of the living body to be measured to the detecting probe and nothing about the pressure and the temperature of the area of the living body is discussed. For this reason, should the posture of the living body (for example, the orientation of the hand in the case where the area of the living body to be measured comprises a portion of the palm of the hand) change, and/or should the temperature environment change, measurements of the biodata would correspondingly change, eventually resulting in deviation in measured biodata accompanied by reduction in accuracy of the biodata.
Also, with the prior art optical biodata measuring apparatus, another problem has been found in that the contact of the area of the living body with the detecting probe is not sufficient and the biodata measured tend to vary accompanied by reduction in accuracy of the measured biodata.
In the meantime, it often occurs that the biodata measurement is to be performed subject to the area of the living body in a condition in which no blood component is contained in the area of the living body. In such case, the prior art optical biodata measuring apparatus requires complicated and time-consuming procedures because the flow of the blood within the area to be measured must be interrupted by any means (for example, tightly fastening a portion of the living body adjacent the area to be measured) prior to commencement of the biodata measurement.